Multiple blade scrap saw for pipe mill

ABSTRACT

The disclosure is directed to a new scrap kick-out conveyor for a continuous buttweld pipe mill installation. The pipe mill includes a scrap cut-off saw, located between the welding mill and the subsequent processing mills, and the kick-out conveyor is located downstream of the scrap saw. The conveyor includes stock advancing rolls, for supporting and advancing the pipe stock, and inboard and outboard guide rails for laterally confining the pipe. Means are provided for retracting selected portions of the outboard guide rail and for diverting selected portions of the inboard rail to lie across the pass line, such that the oncoming scrap section is diverted off of the conveyor. An inclined discharge apron is provided adjacent the outboard guide rail, leading to a scrap bin. The retractable portion of the outboard guide rail is arranged to retract downwardly, and is provided with an inclined upper surface to facilitate gravity discharge of the scrap sections.

This is a division of application Ser. No. 661,371, filed Feb. 25, 1976,now U.S. Pat. No. 4,022,092.

BACKGROUND AND SUMMARY OF INVENTION

In the production of continuous buttweld pipe, strip stock, known asskelp, is fed from a coil, through a heating furnace, and then through aforming and welding mill. In the forming and welding mill, the red hotskelp is first formed into a tube, in a multiple stand forming mill, andthen the opposite edges of the skelp are brought together under pressureto form a weld.

Properly formed and buttwelded tubing typically is conveyed from thecontinuous buttweld mill to a stretch reducing mill, in which the pipeis subjected to a combination of rolling pressure and longitudinaltension, to produce a finished pipe having desired diameter and wallthickness characteristics. On the downstream side of the stretchreducing mill, there is typically provided a flying hot saw, whichsevers the stretch reduced pipe to the desired length, after which theindividual lengths are conveyed to a cooling bed. All of the foregoingis well known and conventional.

In the initial start up of the continuous buttweld mill, a considerableamount of scrap pipe is produced while the skelp is being brought up theproper welding temperature. Where a stretch reducing mill is employeddownstream of the forming and welding mill, it is not feasible to permitthe scrap pipe to enter the stretch reducing mill, because of possibledamage to the mill. Accordingly, it is necessary for the scrap portionsof the pipe to be cut off and removed between the forming and weldingmill and the stretch reducing mill. In the past, this has necessitated aconsiderable amount of heavy manual work, typically with the use oftorches to cut the scrap into sections, which are then manually draggedout of the way and eventually picked up for reprocessing. Where astretch reducing mill is not employed in the line, it is sometimespossible to utilize the regular production flying cut-off saw to severthe scrap sections during start up. However, even this is sometimes notpossible, and in all events a substantial amount of heavy manual work isrequired in handling and removing the scrap sections servered by theproduction saw.

Pursuant to a related invention, a novel and improved scrap saw isprovided, which is suitable for installation downstream of the formingand welding mill (and upstream of a stretch reducing mill, if used). Thescrap saw includes rotary frame mounted above the pass line and carryingcutting saws at each of two ends, such that two cuts may be made foreach revolution of the frame. This is particularly desirable in thehandling of scrap, inasmuch as it permits the scrap to be severed intoshort, easily manageable lengths, while still permitting the rotary sawframe to be rotated at appropriately low speeds.

The dual rotary saws are driven by a stationary drive motor, located onthe main frame of the equipment. This enables a significant reduction inthe weight of, and a corresponding simplfication of the rotating partsof the saw mechanism.

The the individual saw blade mechanisms are supported by spaced inboardand outboard frame housings, which are fixed to a common shaft andmounted for rotation in unison. One of the frame housings encloses adrive train for rotating the saw blades, while the other housingencloses an orienting mechanism for maintaining the saw blades in avertical plane at all times.

A synchronous cam arrangement is provided for supporting the pipedirectly underneath the cutting area of the saw blades. The cam isarranged to rotate in accordance with the rotations of the saw frame,such that the pipe is engaged and raised into cutting position as a sawblade moves through the lowermost portions of its arc.

The entire scrap saw mechanism is mounted on slideways, for movementbetween operative and retracted positions. When the mechanism is in itsoperative or working position, it is clamped securely to its slideways,for maximum rigidity of the mounting. For retracting and advancingmovements, the clamping facility is released.

In the system of the invention, there is included an advantageouskick-out arrangement in the pipe conveying system, downstream of thescrap saw, enabling the short, cut-off scrap sections to be kicked outof the conveyor line and discharged into a reception bin.

For a more complete understanding of the above and other features andadvantages of the invention, reference should be made to the followingdetailed description of a preferred embodiment and to the accompanyingdrawings.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a highly simplified plan layout of a pipe mill, including acontinuous buttweld mill, scrap cut-off saw and kick-out section,stretch reducing mill, production cut-off saw, and cooling beds.

FIG. 2 is a side elevational view, partly in section, of a dual rotaryscrap saw, as utilized in the system of FIG. 1.

FIG. 3 is a cross sectional view as taken generally on line 3--3 of FIG.2.

FIG. 4 is a cross sectional view as taken generally on line 4--4 of FIG.3.

FIG. 5 is a cross sectional view as taken generally taken on line 5--5of FIG. 4, illustrating the dual rotary saw in a plurality of positions.

FIGS. 6(a)-6(i) are a sequence of views showing the relationship ofrotary saw and pipe supporting cam, during the interval in which the sawblade is traveling through its cutting positions.

FIG. 7 is a front elevational view illustrating the discharge endsection of the forming and welding mill, provided with means forsynchronizing the discharge of pipe from the mill with the speed ofoperation of the rotary scrap saw.

FIG. 8 is a side elevation of the equipment shown in FIG. 7, takenpartly in section along line 8--8 of FIG. 7.

FIGS. 9A and 9B, together, constitute a top plan view of a kick-out andreceiving section for the scrap pipe cut-off sections formed by thescrap saw.

FIG. 10 is a cross sectional view as taken generally along line 10--10of FIG. 9B.

FIGS. 11 and 12 are cross sectional views as taken generally along lines11--11, 12--12 respectively of FIG. 10.

FIGS. 13 and 14 are fragmentary cross sectional views as taken generallyon lines 13--13, 14--14 of FIG. 12.

DESCRIPTION OF A PREFERRED EMBODIMENT

Referring now to the drawings, and initially to FIG. 1 thereof, thereference numeral 10 designates generally the furnace section of acontinuous buttweld pipe mill. The furnace receives skelp from asuitable supply (not shown), brings it to appropriate temperature, anddischarges it into a forming and welding mill generally designated bythe reference numeral 11. The red hot skelp, after being formed into atube and buttwelded to form a pipe, travels through a scrap saw inletconveyor section 12, through a scrap saw section 13 and scrap kick-outsection 14, all to be described hereinafter. During normal continuousproduction operations, the scrap saw and scrap kick-out sections areinoperative, and the buttwelded pipe passes on through these sectionsand into a stretch reducing mill generally designated by the referencenumeral 15. In the stretch reducing mill, the buttwelded pipe is rolledand elongated in accordance with known techniques, to achieve a desiredcombination of final diameter and wall thickness.

Upon discharge from the stretch reducing mill, the pipe passes through aproduction flying hot saw section, generally designated by the referencenumeral 16. The production hot saw may be of conventional design, and isarranged to sever the finished pipe sections into appropriate commerciallength. Thereafter, the individual cut sections of finished pipe arecarried to a cooling bed, generally designated by the reference numeral17. In a typical cooling bed, the individual pipe sections areprogressed gradually from one side to the other of the bed, beingpermitted to cool gradually during such progression. The pipe sectionsare then removed from the cool side of the bed 17 and taken forshipment, storage, or further processing.

Although the continuous buttweld pipe mill is designed foruninterrupted, steady-state operation, there is always a transitionperiod during the initial start up of the mill, when the skelp is beingbrought up to the desired operating temperature. During this start upphase, the leading end of the skelp welds imperfectly if at all in theforming and welding mill and must be scrapped. In the past, this hasoccasioned extensive manual labor, involving strenuous and hazardouswork and considerable expense.

Pursuant to a related invention, an improved form of rotary hot saw 13is provided, for installation in the region immediately downstream ofthe forming and welding mill and useable in conjunction with the kickout section 14. During the transitional start up phase of the pipewelding mill, the rotary scrap saw 13 is put into operation and servesto continuously sever the oncoming, imperfectly formed pipe into short,easily handleable sections, which are automatically kicked out of theconveyor system and collected in receiving bins 18. Once the system hasbeen brought to its steady-state condition and is deliveringspecification pipe, the scrap saw is rendered inoperative and withdrawnfrom the area of the pass line, enabling the welded pipe to proceedcontinuously on through the stretch reducing mill and to the productionhow saw 16.

The scrap saw is of a unique and advantageous construction, such that,in a practical assembly useful in the environment of a continuousbuttweld mill, a rotating saw structure may be provided with dual ormultiple saw blades, for severing the leading end scrap section intodesirably short, easily handleable sections. Referring now to FIGS. 2-5,the reference numeral 19 represents generally a base structure, on whichis slideably supported a frame assembly 20. The frame assembly 20 mountsa support housing 21 carrying spaced bearings 22, 23 which rotatablyjournal a heavy tubular main shaft 24. A portion 25 of the main shaftextends in cantilever fashion forward of the housing 21 and mounts infixed relation spaced inboard and outboard saw frame housings 26, 27.The saw frame housings desirable are of elongated form, are parallel toeach other, and are symmetrically related to the heavy main shaft 24, soas to provide a generally balanced assembly.

As shown best in FIG. 4, the frame housings 26, 27 are provided at theirouter ends with bearing assemblies 28, 29, which rotatably mount sawsupporting assemblies each comprising shaft sections 29, 30 and a gearhousing 31. A portion 29a of the shaft section 29 extends through thebearing 28 and into the frame housing 26. The shaft portion 29a mounts agear 32 which engages, through an idler pinion 33, a fixed ring gear 34.The ring gear is secured by bolts 35 to collars 36 and 37 forming fixedparts of the main shaft support housing 21.

With the ring gear 34 being thus fixed, when the saw frame housings 26,27 are rotated along with the main shaft 24, the gears 32 tend to berotated in relation to the housings. The gears 32 are selected to be thesame size as the ring gears 34, such that, as the frame housing rotate,the rotational orientation of the gears 32 remains constant with respectto a fixed reference, thus maintaining a constant orientation of theshaft-housing assembly 29-31.

Rotation of the main shaft 24 at a controlled speed is effected by meansof a worm gear 38 keyed to the shaft and driven by a worm 39. The latteris supported by bearings 40, 41 in the main housing 21 and is connected,by way of a torque limiting clutch 42, to a drive motor 43. As will bereferred to hereinafter, the drive motor 43 is controlled in a manner toachieve appropriate synchronism between the rate of rotation of the sawframe housings 26-27 and the advancing movement of the emerging pipe.

As reflected particularly in FIG. 5, the gear housings 31 incorporatespaced bearings 44, 45, which rotatably support high speed shafts 46,47. The shafts 46, 47 have portions which project from opposite ends ofthe gear housings. On one end of each of the shafts 46, 47 is mounted asaw blade 48, 49. At the opposite end of each shaft is mounted acombined counterbalance and fly wheel 50, 51.

Each of the high speed shafts 46, 47 mounts a bevel gear 52, meshingwith a similar bevel gear 53 (see FIG. 4). The bevel gears 53 are keyedto the end of drive output shafts 54 journaled by bearings 55, 56 withinthe hollow shaft sections 30. The drive output shafts 54 includeportions projecting into the outboard frame housing 27 and mountingpinions 57. The pinions 57 are driven through idler gears 58 from acommon main drive gear 59 which is concentric with the main shaft 24.

As reflected in FIGS. 2 and 4, the main drive shaft 24 is of tubularform and mounts spaced bearings 60, 61 at its opposite ends. Anelongated, coaxially disposed common drive input shaft 62 extendsthrough the hollow interior of the main shaft 24, and is supported bythe spaced bearings 60, 61. At its outboard end, the drive input shaft62 is connected to the common drive gear 59. Accordingly, upon rotationof the shaft 62, the respective saw blades 48, 49 will be driven throughthe gear trains 57, 58, 59, the drive output shafts 54 and therespective pairs of bevel gears 52, 53. The drive input shaft 62 isdriven at relatively high speed, independently of rotation of thetubular main drive shaft 24, by means of a suitable drive motor 63 (FIG.2), which drives the shaft 62 through pulleys 64, 65 and a belt 66.

As reflected in FIGS. 2-5, the respective gear trains controlling therotation of the saw blades 48, 49, on the one hand, and controlling theconstant rotational orientation of the saw blades in a vertical plane,on the other hand, are completely enclosed in the frame housings 26, 27,so as to be protected from the working environment.

As reflected in FIG. 3, the outboard end of the shaft section supportingthe worm 39 is connected, through pulleys 66, 67 and a timing belt 68,to a gear reducer 69 (FIG. 2). The gear reducer 69 is connected throughuniversal joints 70, 71 and a connecting shaft 72 to a cam operatingshaft 73, which is journaled in a movable bearing assembly 74. The shaft73 carries, at its outboard end, a pipe positioning and confining cam75, which is comprised of a main cam body 76 and spaced guide flanges77. The cam 75 is positioned directly under the pass line of the formedpipe and is arranged to both lift and laterally confine the pipe duringthe moments when the saw blade 48 or 49 is passing through the cuttingportion of its circular path. By means of the gear reducer 69, the cam75 is accurately timed in relation to the rotary saw frame 26, 27, so asto be brought into its lifting and confining orientation when either ofthe two saw blades approaches its cutting position.

With particular reference to FIGS. 6(a)-6(i), there is illustrated atypical sequence of cam-saw blade coaction during the cutting sequence.FIG. 6(a) illustrates the position of the cam as the saw blade descendsdownward and in a right-to-left direction, moving synchronously with thepipe section P. The cam 75, rotating in a counterclockwise direction,has been brought into a position in which the pipe has just begun to besupported by a riser surface 78. At this stage, the pipe is confinedbetween the spaced flanges 77. In FIG. 6(b), the saw blade is enteringthe pipe, which continues to be supported and confined by the cam and isbeing raised slightly by the riser surface 78. Progressing through FIGS.6(c), (d) and (e), the pipe is gradually raised to the crest portion 79of the cam surface, while the saw blade continues to descend. The sawblade is now well below the upper edge of the flanges 77 and, toaccommodate this, the flanges are notched as at 80.

As reflected in the sequence of FIGs. 6(e)-6(g), the synchronization ofthe cam and saw blade is such that the saw blade moves slightly inadvance of the crest 79 of the cam surface. Accordingly, when the pipeis supported at its maximum height, the riser surface 78 drops away fromthe lower edge of the pipe, permitting the saw to pass completelythrough the lower surfaces of the pipe to complete the severance. Thearc of the blade then begins to effect its upward withdrawal from thepass line, and the continued rotation of the cam brings a decliningsurface 81 under the pipe, lowering the pipe to its normal pass line.Throughout the remainder of its rotation, the cam need not, andpreferably does not, contact the pipe, which remains supported on itsregular conveyor means.

Since the cam 75 is required to be closely cooperative with the sawblades, provision is made for adjusting the height of the cam toaccommodate typical variations in saw blade diameter, resulting fromoccasional sharpening for other reasons. Accordingly, the bearingassembly 74 is mounted on a linkage 82 pivoted at 83 on a frame member84. The linkage 83 is also connected at 85 to a manually operated screwjack mechanism 86 carried by a frame member 87. By manipulation of thehand operated screw jack 86, the linkage 82 may be pivoted in acounterclockwise or clockwise direction to effect limited verticaladjustment of the cam mounting shafts 73. This limited vertical motionis accommodated by the universal joints 70, 71, as will be understood.

In a typical intended operating sequence, the scrap saw arrangementillustrated in FIGS. 2-6 is utilized only during the start up procedures-- a transitional period in which the pipe is imperfectly formed and isscrapped. Once on-specification pipe is being produced by the formingand welding mill, the scrap saw is rendered inoperative and the pipe ispermitted to pass through the stretch reducing mill 15 and onto theproduction cut-off saw 16. Initially, when the scrap saw is to be takenout of service, rotation of the saw frame housings 26, 27 is stoppedwith the housings generally parallel to the axis of the pipe, so as tomaintain both saws well out of the way of the moving pipe. The cam 75will likewise be oriented in a retracted rotary position, with theraiser portions 78, 79 and the flanges 77 well removed from the passline. Appropriate means, such as a rotary switch device 90 (FIG. 2),which is connected in with the cam and saw housing drive, may beutilized for effecting the desired orientation of the saw frames andlifting cam when shutting down the scrap saw.

Inasmuch as the pipe forming line may be maintained in continuousoperation for long periods of time after start up, it is advantageous tophysically retract the scrap saw from the area of the pipe pass line, soits components are somewhat protected from the heat of the red hot pipe.

To this end, the base 19 is provided with dovetail slide surfaces 91, 92(see FIG. 3) which respectively support and guide the housing 20 and theequipment supported thereon. The supporting frame work 93 for thehousing includes a plurality of fixed guide blocks 94, on one side, anda plurality of wedge-like movable guide blocks 95 on the opposite side.The movable guide blocks are arranged to be moved vertically byhydraulic cylinders 96. In order to advance the scrap saw to itsoperative position, a fluid cylinder 97, mounted to the base 19 at 98and connected to the housing 20 at 99, is actuated in an extendingdirection to move the unit forward on the base 19. When the unit isproperly positioned, the cylinders 96 are actuated to draw the movablewedges 95 tightly into position, effectively locking the saw unit in itsoperative position. These hydraulic cylinders 96 are subsequentlyreleased, to lower the wedge blocks 95, in order to permit the unit tobe retracted from the pass line.

To advantage, a guard member 100, of generally inverted U-shapedconfiguration is mounted to and extends forward from the main housing20, just above the level of the guide surfaces 91, 92. When the unit isretracted, this cover plate 100 is positioned over the top of theotherwise exposed guide surfaces, to keep the surfaces free of hot metalparticles and other foreign matter which may otherwise tend toaccumulate on and follow the guide surfaces during the periods of nonuseof the scrap saw. A similar cover member 101 may be provided at therear, if desired.

With reference now to FIGS. 7 and 8, there is shown an improvedarrangement for synchronization of the rate of rotation of the sawhousings 26-27 with the rate of emergence of pipe from the forming andwelding mill. In this respect, during the start up phase, the skelp isadvanced at a low rate of speed from the forming and welding mill, andthis is gradually increased until, eventually, steady-state conditionsare reached. At the outset, the drive motor 43, which rotates the scrapsaw frame 26-27, is electrically synchronized with the drive motor forthe last stand of the forming and welding mill (not shown). Thisprovides a reasonable approximation of speed of travel of the pipe atthe scrap saw. However, as soon as the forming and welding millcommences to form round pipe, a more accurate synchronization isachieved by directly contacting the pipe with a measuring wheel 103.

The measuring station desirably is located at the upstream end of thescrap saw inlet conveyor 12, and is so constructed as to locate thewheel relatively close to the discharge end of the forming and weldingmill. To advantage, the entire measuring wheel assembly is mounted on abracket 104, which is pivoted at 105 to the stationary frame structure107. Arms 108 are attached to the back of the bracket 104 and areconnected at 109 to the operating rod 110 of a fluid cylinder 111. Whenthe cylinder is retracted, the entire bracket 104 is tilted upward andaway from the pass line of the pipe, designated by the numeral P, whichis issuing from the forming and welding mill and is supported onconveyor rolls 112 of the inlet conveyor structure 12. When the cylinder111 is actuated to extend, the bracket 104 is tilted downward andforward to an operating position, as determined by adjustable stop bolts113 engaging stop lugs 114.

The bracket 104 includes a cantilevered beam section 115, which extendstoward the forming and welding mill and carries a bracket 116 at itsouter end. The bracket 116 pivotally mounts a frame 117, which hasbearings 118, 119 for journaling the measuring wheel 103.

At the end opposite the pivot bracket 116, the arm structure 117 isconnected to a fluid cylinder 120, whose operating rod 121 is connectedto the bracket 104 at 122. The cylinder 120 controls the pressure withwhich the measuring wheel 103 is brought to bear against the moving pipeP.

During the initial start up phase, the stock issuing from the formingand welding mill may be badly deformed and perhaps not even closed atthe seam. During this phase, the cylinder 111 is retracted to pivot theentire measuring wheel mechanism out of the way. As soon as the pipebegins to assume a round form, the cylinder is extended, to bring themeasuring wheel into contact with the pipe, as shown in FIGS. 7 and 8.The rotation of the wheel will thereafter reflect precisely the speed ofadvance of the pipe issuing from the mill. This is detected by atachometer 123 driven by the measuring wheel, and an appropriate signalis derived from the tachometer for accurate synchronization of the scrapsaw.

In FIGS. 9-14, there are shown structural details of an automatic scrapkick-out and receiving arrangement according to the invention, which islocated just downstream of the scrap saw (see item 14, FIG. 1) and isoperative in conjunction with the scrap saw to automatically kick out ofthe conveyor system the sawed scrap sections. In the illustratedarrangement, the automatic kick-out structure includes a saw outletconveyor section comprising a plurality of pipe supporting and conveyingrolls 130 driven by motors 131 and arranged to support and advance thepipe at suitably spaced intervals. Positioned above and on oppositesides of the conveyor rolls 130 are inner and outer guide railassemblies 132, 133 respectively which provide lateral confinement forthe pipe as it traverses the kick-out section. As will be described morefully, the outer guide rail assembly 133 is retractable to permit alateral diversion of the scrap sections. Likewise, the inner guide railassembly 132 includes one or more pivotally mounted diverter rails 134,135 arranged to be selectively disposed at an angle across the pass lineof the pipe, in order to divert a sawed off pipe section off of theconveyor rolls, over the retracted outer guide rail 133 and into a scrapbin 136.

As shown particularly in FIG. 10, an inclined apron 137 is mountedadjacent the kick-out conveyor section, having one edge alongside theretractable guide rail 133 and its opposite edge above and adjacent oneside of the scrap bin 136. In the illustrated arrangement, the scrapdischarge arrangement includes two kick-out sections and two scrap bins,so that one of the bins may be receiving scrap sections while the otheris being unloaded. The apron 137 typically will extend the full lengthof the kickout section, being provided with abutment guides 138, 139positioned near the downstream ends of the scrap bins. Thus, when a pipesection is discharged from the conveyor onto the inclined apron 137, itwill roll and/or slide into the bin on the upstream side of the abutmentguide.

To advantage, the retractable outer guide rail assembly 133 is mountedfor generally vertical retracting movement by means of a plurality ofcrank levers 140, 141 pivoted at 142, 143 on the conveyor framestructure 144. The levers 140, 141 are pivotally connected at 145, 146to the guide rails assembly 143 and are also pivotally connected attheir opposite ends to a horizontally movable tie rod 147. A projectingportion 148 of one of the crank levers 140 is connected by means of atoggle linkage 149, 150 to a hydraulic cylinder 151 for pivoting thecrank lever. When the cylinder 151 is retracted to a limit position, thetoggle linkage 149, 150 is straightened, causing the lever 140 to bepivoted to a counterclockwise limit position to raise the guide rail 133to its guide position. By means of the tie bar 147, all of the othercrank levers 141 (there are as many as is appropriate to the length ofthe guide rail) are pivoted in a similar manner, so that the guide railis moved uniformly throughout its length. When the cylinder 151 isenergized to extend, the toggle linkage passes through its dead centerposition and pivots over against a resilient abutment stop 152. Thiscauses the lever 140 to pivot clockwise through a substantial angle,along with all of the connected levers 141, lowering the guide rail 133.FIG. 10 illustrates the raised and retracted positions of the guide rail133. In the upraised position, illustrated in phantom lines, the sidewall 153 of the guide rail confines the pipe P passing over the conveyorwheels 130. In the retracted position, the outwardly slanted uppersurface 154 of the guide rail serves as a transition surface, permittinga pipe section to roll from the rolls 130 onto the apron 137.

As best illustrated in FIGS. 9A and 9B, the diverter rail sections 134,135 are pivotally connected at 155, 156 to the inner guide railstructure and are operably connected to fluid cylinders 157, 158.

When the scrap saw is in operation, the outer guide rail 133 isretracted and one of the cylinders 157, 158 is actuated to pivot one ofthe diverter sections 134, 135 across the pass line of the pipe. Assuccessive individual pieces of cut-off scrap pipe are conveyed alongthe pass line, they will engage the angularly disposed diverter memberand be rolled off onto the apron 137 and into the appropriate dischargebin 136. When one bin becomes filled with scrap sections, the seconddiverter member is brought into use and the first diverter member isretracted to its normal position. Scrap sections will then be directedinto the second discharge bin, while the first is removed and emptied.

When the forming and welding mill is operating on a steady-state basis,and the scrap saw is taken out of service, the kick-out section willcontinue in operation momentarily, until the last section of scrap pipehas been diverted from the pass line, after which the diverter sectionis immediately retracted to permit passage of the specification pipe. Atthis time the outer guide bar assembly 133 is raised to its normalposition.

The system of the invention also includes, for use in conjunction withthe rotating scrap saw, an advantageous form of outlet conveyor withscrap kick-out means. The mechanism includes a conveyor means, typicallya plurality of trough shaped rolls, in conjunction with inboard andoutboard guide rails. The outboard guide rail is selectivelyretractable, and the inboard guide rail includes one or more pivotablediverter sections. When the scrap saw is in operation, the outboardguide rail is retracted and one of the inboard sections is moved todiverting position, such that the individual pieces of scrap pipe arekicked off the conveyor, down an inclined apron and into a disposal binas they are carried along the conveyor axis. When steady-stateconditions are reached, the guide rails are brought back to their normalor guiding positions and function to guide the specification pipe on tothe next station, typically a stretch reducing mill.

It should be understood, of course, that the specific form of theinvention herein illustrated and described is intended to berepresentative only, as certain changes may be made therein withoutdeparting from the clear teachings of the disclosure. Accordingly,reference should be made to the following appended claims in determiningthe full scope of the invention.

We claim:
 1. A scrap kick-out conveyor for a continuous buttweld pipemill installation provided with a scrap cut-off saw between the formingand welding mill and subsequent processing mills, which comprises(a)stock advancing conveyor rolls located on the pass line downstream ofthe scrap saw, (b) inboard and outboard lateral guide rails on oppositesides of the pass line for guiding and confining pipe stock supported onsaid conveyor rolls, (c) means for retracting at least selected portionsof the outboard guide rail, (d) means for diverting at least selectedportions of the inboard guide rail to lie at an angle across the passline to divert oncoming cut scrap pipe sections off of the outboard sideof the conveyor, (e) means for receiving diverted scrap pipe sectionsfor disposal, and (f) an inclined apron provided adjacent the outboardguide rail, (g) said selected portions of the outboard rail beingdownwardly retractable and having a downwardly inclined upper surface tofacilitate gravity discharge of scrap pipe diverted from the pass line.